In general, metal matrix composites (MMCs) are known. MMCs typically include a metal matrix reinforced with fibers either particulates, whiskers, short fibers or long. Examples of metal matrix composites include aluminum matrix composite wires (e.g., silicon carbide, carbon, boron, or polycrystalline alpha alumina fibers embedded in an aluminum matrix), titanium matrix composite tapes (e.g., silicon carbide fibers embedded in a titanium matrix), and copper matrix composite tapes (e.g., silicon carbide or boron carbide fibers embedded in a copper matrix).
One use of metal matrix composite wire is as a reinforcing member in bare overhead electrical power transmission cables is of particular interest. One typical need for cables is driven by the need to increase the power transfer capacity of existing transmission infrastructure.
Desirable performance requirements for cables for overhead power transmission include corrosion resistance, environmental endurance (e.g., UV and moisture), resistance to loss of strength at elevated temperatures, creep resistance, as well as relatively high elastic modulus, low density, low coefficient of thermal expansion, high electrical conductivity, and/or high strength. Although overhead power transmission cables including aluminum matrix composite wires are known, for some applications there is a continuing desire, for example, for aluminum matrix composite wires having improved strain to failure values and/or size uniformity.
The availability of round wires having a more uniform diameter at different points along the length of the round wires is desirable for providing cable constructions with a more uniform diameter. Thus, there is a need for a substantially continuous metal matrix composite wire having a round cross-section and uniform diameter and methods for making such a substantially continuous metal matrix composite wire.